Breath holding index in detection of early cognitive decline

The aim of the study was to evaluate role of breath holding index (BHI) as a functional parameter for intracranial subclinical atherosclerotic changes in recognizing patients who are at risk for developing cognitive impairment of the vascular type. We included 60 volunteers divided into 3 groups according to age and presence of cognitive impairment (healthy subjects 30–40 years old, controls 60–70 years old and subjects with mild cognitive impairment 60–70 years old). We excluded individuals with moderate and severe carotid stenosis. There was a decreasing trend in the mean blood flow velocities of the intracranial blood vessels due to age increase, but it was not statistically significant. BHI values were 1.66 ± 0.20 in the first group, 1.35 ± 0.31 in the second and 0.69 ± 0.30 in the third group. There was a statistically significant difference between the first two groups and the group with a mild cognitive impairment (MCI) in Montreal cognitive assessment (MoCA) score (29 ± 1, 27 ± 1 and 19 ± 1 respectively), no statistically significant difference was found in Mini mental state exam (MMSE) score (29 ± 1, 28 ± 1, and 28 ± 1 respectively). After regressing out age and conventional vascular risk factors, we found a good correlation between the decreasing trend in BHI values and MoCA score, and no statistically significant correlation between the BHI values and MMSE score. Results of our study show that BHI test as a parameter of impaired cerebrovascular reactivity (intracranial small vessel wall dysfunction) might differentiate individuals with early cognitive decline from healthy subjects.